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I'm playing around with a virtual network inside of VirtualBox 5.0.26 (with Guest Additions). I am using dnsmasq for dhcp and dns and the machines all apear to be allocated their network information correctly, however, I can only ping machines in the network using their hostnames, but not their fully qualified domain names and I can't figure out why.

My VirtualBox has 2 networks configured:

  • NAT Network [10.0.2.0/24], Supports DHCP

  • Host Only Network Adapter [192.168.62.1 / 255.255.255.0], No DHCP

In my Virtual Box network I have a couple of dummy machines: 2 Centos boxes with minimal installs + net-tools, bind-utils and dnsmasq; and an Ubuntu box:

Centos1:

- Minimal Centos 7 install + net-tools, bind-utils, dnsmasq
- /etc/hostname =>
     centos1
- /etc/hosts =>
     127.0.0.1 centos1.mytestnetwork.lab centos1
- /etc/resolv.conf
     # Generated by NetworkManager
     search home.local
     nameserver 10.1.10.10 #IP of legit DNS server
     nameserver 10.1.10.11 #IP of legit DNS server
     nameserver 192.168.62.10
     # NOTE: the lic resolver may not support more than 3 nameservers
     # The nameservers listed below may not be recognized
     nameserver: 127.0.0.1
- /etc/resolv.conf.dnsmasq
     127.0.0.1
- Primary NIC [enp0s3] connected to NAT Network configured for dhcp
- Secondary NIC [enp0s8] connected to Host Only Network with static IP 192.168.162.10

Centos2:

- Minimal Centos 7 install + net-tools, bind-utils
- /etc/hostname =>
    centos2
- /etc/hosts =>
    127.0.0.1 localhost localhost.localdomain
    ::1       localhost localhost.localdomain
- Primary NIC [enp0s3] connected to NAT Network configured for dhcp
- Secondary NIC [enp0s8] connected to Host Only Network configured for dhcp.

Ubuntu1:

- Ubuntu 14.04 LTS default install with default configuration

On Centos1, the content of my /etc/dnsmasq.conf file is as follows:

resolv-file=/etc/resolve.conf.dnsmasq
bogus-priv
local=/mytestnetwork.lab/
domain=mytestnetwork.lab
interface=enp0s8
no-hosts
addn-hosts=/etc/hosts.dnsmasq
expand-hosts
dhcp-range=192.168.62.50,192.168.62.250,255.255.255.0,24h

Both machines appear to be allocated their IP and domain name correctly from dnsmasq when they boot up, so:

Centos2.MyTestNetwork.lab [192.168.162.51]
Ubuntu1.MyTestNetwork.lab [192.168.162.52]

Both machines are listed in the /var/lib/dnsmasq/dnsmasq.leases file as I would expect.

1471010530 00:00:27:d4:ce:8d 192.168.62.51 centos2 *
1471010650 00:00:27:6d:12:95 192.168.62.52 ubuntu1 *

Checking Centos2 and Ubuntu1's /etc/resolv.conf files, I see Centos1's IP address listed in the nameserver list on both.

If I do an nslookup from either machine using just the host name, and tailing the /sys/log/messages I see the dns request come into dnsmasq, nslookup lists the correct DNS server the IP address is resolved correctly. I can ping using just the hostname.

;; Got SERVFAIL reply from 10.1.10.11, trying next server
;; Got SERVFAIL reply from 10.1.10.10, trying next server
Server:       192.168.62.10
Address:      192.168.62.10#53

Name:   ubuntu1
Address: 192.168.62.52 

If however, I do an nslookup using the fqdn, no dns request comes into dnsmasq and the machine cannot be pinged.

Server:       10.1.10.11
Address:      10.1.10.11#53

** server can't find ubuntu1.mytestnetwork.lab: NXDOMAIN

I'm confused why it gives an NXDOMAIN in this case and doesn't try the next server until it finds the IP rather than give up at the first hurdle.

0

I don't know if this is the right answer to this question, but this solution appears to resolve my issue, perhaps someone can comment if there's a better or more correct solution:

On Centos1, change the primary network card (enp0s3) from DHCP to static IP configuration by editing /etc/sysconfig/network-scripts/ifcfg-enp0s3

BOOTPROTO=none
ONBOOT="yes"
IPADDR=10.0.2.24
NETMASK=255.255.255.0
GATEWAY=10.0.2.1
DNS1=127.0.0.1
DNS2=10.1.10.11
DNS3=10.1.10.10

Then sudo systemctl restart network or ifdown enp0s3 and ifup enp0s3

This in turn modifies my /etc/resolv.conf

# Generated by NetworkManager
nameserver 127.0.0.1
nameserver 10.1.10.11
nameserver 10.1.10.10

and I can now remove /etc/resolv.conf.dnsmasq and comment out the reference to it in my /etc/dnsmasq.conf

I can now ping by fqdn and by hostname alone.

Ideally, I would like my primary network card to be DHCP... but I can live without it if this is the only way.

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